The present invention relates generally to secondary tillage implements used in agriculture and, more specifically to a soil conditioning rotary reel for use behind secondary seedbed preparation tools. Another design is disclosed for use in primary tillage operations, i.e., such as behind primary tillage tools like chisel plows or heavy offset tandem discs.
As used herein, “primary tillage” refers to tillage where the ground working is deeper and the soil is turned, as for example, with moldboard and chisel plows, at depths greater than four inches. “Primary tillage” is distinguished, for example, from secondary tillage and various cultivation techniques such as disks, “spider” wheels and sweeps, as well as combinations of devices that normally cultivate the surface to nominal depths of two inches, but as deep as three to four inches. In general, primary tillage operations are performed on compacted soil after crop harvest, so such operations may advantageously create clods of larger size and less firming to maintain moisture content. On the other hand, secondary operations are directed toward the creation of an idealized seedbed, i.e., smaller clods, more soil firming and a smooth level surface.
For many years, harrows with either spikes or coil tines have been mounted to the rear of seedbed preparation tools to level and firm the soil and to promote moisture conservation. Similarly, in the past, for clod crushing and further firming, rollers with cast iron wheels have been pulled across the partially prepared seedbed. However, for medium and small clods, such equipment does not exhibit much soil-pulverizing action and additionally tends to push such clod(s) into the soil.
More recently, rotary pulverizing reels have been used that are from 10 to 14 inches in diameter. A series of bars are welded on a spiral lengthwise across the reel. These bars can be either rounds of approximately ¾ to 1 inch in diameter, or flat bars that are, for example, ¼×1½ inches. These units can be either pull-type, as an additional unit behind the secondary tillage machine, or mounted by arms to the rear of the secondary tillage machine. The bars are welded on in a slight spiral to avoid bumping and “chunking” through the field as it is pulled. As the bars come down to the soil there is a beating action caused by the edge of the bar striking the clod(s). As the reel bottoms out it also creates a firming action to the soil.
The flat bars are generally configured so there is an approximate 3–4 inch space between successive bars. The bars are also positioned on the reel so that if a straight edge is laid against the flat part of the bar the line of the straight edge will not go through the centerline of the reel. They are positioned in this way so that as they come down they provide more of a firming action on the soil and do not scoop the soil as they leave the rear side of the reel.
Furthermore, many types of drag harrows have been used behind primary tillage tools, such as moldboard and chisel plows, to break large clods and smooth out the soil surface. Chisel plows leave a large amount of residue near the surface. Harrows pull some of the partially buried residue out. They also bunch residue. Reels do not drag residue.
It would be a distinct advantage to have available a tool that breaks down clods and firms the soil, while avoiding the aforementioned problems and difficulties.